A significant percentage of individuals who initiate opioid agonist treatment with buprenorphine lapse to illicit opioid use within a matter of days. Very few of these early lapsers are able to become consistently illicit opioid-free during their treatment, and often leave treatment and relapse to drug use with its attendant HIV risk. We propose that inability to tolerate the distress of opioid withdrawal and the negative affect associated with early abstinence are key factors in early illicit opioid lapse and subsequent buprenorphine treatment drop-out. This proposal to prevent early lapse is designed to meet the Stage I objectives of the NIDA Behavioral Therapies Development Program. It will take place in two phases. The Aims of the first phase (Stage Ia) of the project are: - to develop, refine, and pilot test a Distress Tolerance (DT) treatment that utilizes skills based in Acceptance and Commitment Therapy with 10 buprenorphine initiators in an iterative manner to establish feasibility and acceptability. The Aims of the second phase (Stage Ib) of the project are: - to conduct a preliminary randomized trial with buprenorphine initiators (n=60) comparing the distress tolerance treatment (DT) to a health education (HE) comparison intervention, examining: - the effects of DT on both short-and long-term illicit opioid use - the effects of DT on time to first illicit opioid lapse and time to buprenorphine treatment drop-out - the effects f DT on HIV risk behaviors (e.g., sharing of drug injection equipment). This project will develop a well-specified and novel behavioral distress tolerance treatment for buprenorphine initiators to prevent early illicit opioid use lapse, treatment drop-out and return to HIV risk behaviors, the efficacy of which can be tested in future Stage II randomized clinical trials. This research projec will also contribute much- needed knowledge about the relationship between opioid withdrawal, negative affect, distress tolerance, and buprenorphine outcomes.